Why are koalas so cool? Because LL Cool J ama said "knock you out!"
Knock You Out Koala
Explanation
Explain Bear
Listen up, genius. The joke is that LL Cool J, who is a rapper, has a song called "Mama Said Knock You Out!" The joke uses the similar-sounding "Llama said knock you out" to answer why the "koalas so cool." It is not meant to be funny, because you posted it.